The present invention relates to an attitude detection device capable of detecting with high precision an attitude of a machine or equipment in which it is used.
A conventional attitude detection device disclosed in JP-A-6-307805, for example, has a hollow outer spherical body and an inner spherical body rigidly secured in a hollow portion of the outer spherical body with a predetermined layer space therebetween, wherein a fluid conductor is arranged between a first conductive area including an electrode formed over the entire inner side of the outer spherical body and a second conductive area including a plurality of electrodes formed in a dotted pattern on the outer side of the inner spherical body. In this conventional attitude detection device, the fluid conductor can move in the layer space between the first conductive area and the second conductive area to bring one of the electrodes in the second conductive area into electrical contact with the electrode of the first conductive area to detect the attitude of the equipment.
Generally, conventional mechanical watches do not have an attitude detection device. In such a conventional typical mechanical watch, as shown in FIG. 30, the mainspring torque decreases as the spring unwinds from a completely wound state (fully wound state) with the elapse of the operating time. In the case of FIG. 30, for example, the mainspring torque is about 27 g.cm in a fully wound state. The mainspring torque decreases to about 23 g.cm 20 hours after the mainspring is fully wound, and further to about 18 g.cm 40 hours from the fully wound state.
Generally, in a conventional typical mechanical watch, as shown in FIG. 31, as the mainspring torque decreases, the deflection angle of the balance also decreases. For example, in the case of FIG. 31, when the mainspring torque is 25 g.cm,-28 g.cm, the deflection angle of the balance is about 240-270 degrees; and when the mainspring torque is 20 g.cm-25 g.cm, the deflection angle of the balance is about 180-240 degrees.
FIG. 32 shows a tradition of an instantaneous watch error (value representing the accuracy of a watch) as related to the deflection angle of the balance in a conventional typical mechanical watch. Here, the xe2x80x9cinstantaneous watch errorxe2x80x9d refers to a xe2x80x9cvalue representing an amount gained or lost by a mechanical watch per day by assuming that the mechanical watch has been left to stand for one day while maintaining the state and environment, such as the deflection angle of the balance, as they were when the watch error was measured.xe2x80x9d In the case shown in FIG. 32, when the deflection angle of the balance is 240 degrees or more, or 200 degrees or less, the instantaneous watch error loses.
For example, in the conventional typical mechanical watch, when the deflection angle of the balance is about 200-240 degrees, the instantaneous watch error is about 0-5 seconds/day (it gains about 0-5 seconds a day). When the deflection angle of the balance is approximately 170 degrees, the instantaneous watch error is approximately xe2x88x9220 seconds/day (it loses about 20 seconds a day).
FIG. 27 shows a transition over time of the instantaneous watch error in a conventional typical mechanical watch as the spring unwinds from the fully wound state. In the conventional mechanical watch, the xe2x80x9cwatch errorxe2x80x9d indicating the amount gained or lost by the watch per day is obtained by integrating over 24 hours the instantaneous watch error indicated by a thick line in FIG. 27 which is related to the time it takes for the spring to unwind from the fully wound state.
Generally, in the conventional mechanical watch, as the spring unwinds from the fully wound state with the elapse of the operating time, the mainspring torque decreases and the deflection angle of the balance also decreases, which in turn causes the instantaneous watch error to lose. Hence, in the prior art mechanical watch, it is a conventional practice that, to allow for the slowdown that will occur 24 hours of the operating time later, the instantaneous watch error when the spring is fully wound is advanced beforehand such that the xe2x80x9cwatch errorxe2x80x9d indicating the amount gained or lost by the watch in one day will be positive.
For example, in the conventional typical mechanical watch, as shown by a thick line in FIG. 27, the instantaneous watch error is about 5 seconds/day (the watch gains about 5 seconds a day) in a fully wound state. But the instantaneous watch error decreases to about xe2x88x921 second/day (the watch loses about 1 second a day) 20 hours after the mainspring is fully wound, and further to xe2x88x925 seconds/day (it loses about 5 seconds a day) 24 hours from the fully wound state. When 30 hours pass from the fully wound state, the instantaneous watch error becomes approximately xe2x88x9215 seconds/day (the watch loses about 15 seconds a day).
Further, in a conventional typical mechanical watch, the instantaneous watch error when the watch is in a xe2x80x9chorizontal attitudexe2x80x9d and in a xe2x80x9cinverted horizontal attitudexe2x80x9d is faster than the instantaneous watch error when it is in a xe2x80x9cvertical attitude.xe2x80x9d
For example, when a conventional typical mechanical watch is in a xe2x80x9chorizontal attitudexe2x80x9d and in an xe2x80x9cinverted horizontal attitudexe2x80x9d, although the instantaneous watch error in the fully wound state is about 8 seconds/day (the watch gains about 8 seconds a day), as indicated by a thick line in FIG. 33, the instantaneous watch error decreases to about 3 seconds/day (it gains about 3 seconds a day) 20 hours from the fully wound state, to about xe2x88x922 seconds/day (it loses about 2 seconds a day) 24 hours from the fully wound state, and to about xe2x88x9212 seconds/day (it loses about 12 seconds a day) 30 hours from the fully wound state.
In the xe2x80x9cvertical attitudexe2x80x9d, on the other hand, the conventional typical mechanical watch has the instantaneous watch error of about 3 seconds/day (the watch gains about 3 seconds a day) in a fully wound state, as indicated by a thin line in FIG. 33. The instantaneous watch error, however, decreases to about xe2x88x922 seconds/day (the watch gains about 2 seconds a day) 20 hours after the mainspring is fully wound, to about xe2x88x927 seconds/day (it loses about 7 seconds a day) 24 hours from the fully wound state, and further to about xe2x88x9217 seconds/day (it loses about 17 seconds a day) 30 hours from the fully wound state.
It is an object of the present invention to provide an attitude detection device capable of detecting with high precision an attitude of a machine or equipment in which it is used.
It is another object of the present invention to provide a small attitude detection device with high precision that can be used in small precision devices such as mechanical watches.
The present invention is characterized by the attitude detection device which comprises: a case having a hexahedral shape; electrodes arranged one on each inner surface of the case; and a conductive fluid accommodated in the case; wherein the electrodes are insulated from one another.
In the attitude detection device of the invention, it is preferred that the conductive fluid be arranged to assume a state in which it contacts five of the electrodes, a state in which it contacts four of the electrodes, and a state in which it contacts three of the electrodes.
In the attitude detection device of the invention, it is preferred that the electrodes be almost square in shape and their shapes be almost identical.
In another embodiment, the present invention is characterized by an attitude detection device which comprises: a case having a hexahedral shape; electrodes arranged two or more on each inner surface of the case; and a conductive fluid accommodated in the case; wherein the electrodes are insulated from one another.
The present invention is characterized by the attitude detection device which comprises: a case having a hexahedral shape; electrodes arranged two or more on each inner surface of the case; and a conductive fluid accommodated in the case; wherein the electrodes are insulated from one another.